Stabilized liquid peroxygen bleaches based on hydrogen peroxide have been known for some time and employed on an industrial basis in the manufacture and finishing of fabrics. The usual form taken is that of stablized 35 percent hydrogen peroxide solutions. These are currently available from DuPont (Albone 35 CG) and from FMC (Standard 35% H.sub.2 O.sub.2 or Super D 35%) H.sub.2 O.sub.2). The adaptation of these industrial peroxygen bleaches to household use requires dilution to a lower strength, e.g. 6 percent, for safety and ease of use.
Consumer safety considerations make it desirable to color this type of product to clearly identify it as a nonpotable liquid. Pure hydrogen peroxide solutions are visually indistinguishable from water. A blue color is most desirable since, in common domestic usage, the color blue has come to connote a product intended for laundry use. A suitable blue dye must be both stable in the hydrogen peroxide without inducing bleach decomposition and not cause dyeing or staining of any known fiber of fabric likely to be laundered by a housewife.
Most commercially available, or otherwise known, blue dye systems are either degraded by, or cause breakdown of 6 percent hydrogen peroxide. Moreover, it is found that all blue dyes mutually stable with 6 percent hydrogen peroxide are strongly substantive to one or more common types of fibers when incorporated in a stabilized (acidic) liquid peroxygen bleach and used directly on a fabric.